Exposing WS2 nanosheets edge by supports carbon structure: Guiding Na+ intercalation along (0 0 2) plane for enhanced reaction kinetics and stability

Abstract

Growing tungsten disulfide (WS2) on self-supporting carbon fiber cloth is an effective means to enhance the sodium storage. However, it is difficult for WS2 to exhibit high stability and fast reaction kinetics on the surface of carbon fiber cloth. Herein, we construct a composite structure that WS2 nanosheets are grown on the surface of carbon fiber cloth with many gaps. These gaps are poured by pyrolytic carbon structure. The composite structures expose lateral (002) crystal plane of WS2 nanosheets (WS2/CFC@C-P). When WS2/CFC@C-P is evaluated as an anode material for sodium-ion batteries (SIBs), the exposed (002) lateral edge realizes the rapid migration of Na+ with fast reaction kinetics. Moreover, the poured carbon stabilizes expanded WS2 nanosheets to maintain original structure. Under the above merits, WS2/CFC@C-P could provide high reversible capacity (672 mAh g−1 after 200 cycles at 100 mA g−1) and rate capacity (657 mAh g−1at 0.1 A g−1 and 230 mAh g−1 at 2 A g−1). Furthermore, they deliver 297 mAh g−1 after 500 cycles at 2 A g−1 with a low capacity fading of 0.96% per cycle. This work provides a new insight to develop high performance SIBs by introducing the fine regulation of carbon layer.